scholarly journals SARS-CoV-2 screening: effectiveness and risk of increasing transmission

2021 ◽  
Vol 18 (180) ◽  
pp. 20210164
Author(s):  
Jordan P. Skittrall
Keyword(s):  
Viral Transmission ◽  
Testing Strategy ◽  
Behavioural Interventions ◽  
Sample Handling ◽  
Test Sensitivity ◽  
Laboratory Capacity ◽  
Screening Strategies ◽  
Optimal Screening ◽  
Screening Effectiveness ◽  
Selection Of

Testing asymptomatic people for SARS-CoV-2 aims to reduce COVID-19 transmission. Screening programmes’ effectiveness depends upon testing strategy, sample handling logistics, test sensitivity and individual behaviour, in addition to dynamics of viral transmission. The interaction between these factors is not fully characterized. We investigated the interaction between these factors to determine how to optimize reduction of transmission. We estimate that under idealistic assumptions 70% of transmission may be averted, but under realistic assumptions only 7% may be averted. We show that programmes that overwhelm laboratory capacity or reduce isolation of those with minor symptoms have increased transmission compared with those that do not: programmes need to be designed to avoid these issues, or they will be ineffective or even counter-productive. Our model allows optimal selection of whom to test, quantifies the balance between accuracy and timeliness, and quantifies potential impacts of behavioural interventions. We anticipate our model can be used to understand optimal screening strategies for other infectious diseases with substantially different dynamics.

scholarly journals Asymptomatic SARS-CoV-2 testing: predictors of effectiveness; risk of increasing transmission

2020 ◽  
Author(s):  
Jordan P. Skittrall
Keyword(s):  
Behavioral Interventions ◽  
Viral Transmission ◽  
Individual Behavior ◽  
Optimal Selection ◽  
Testing Strategy ◽  
Sample Handling ◽  
Screening Programs ◽  
Test Sensitivity ◽  
Laboratory Capacity ◽  
Selection Of

AbstractTesting asymptomatic people for SARS-CoV-2 aims to reduce COVID-19 transmission. Screening programs’ effectiveness depends upon testing strategy, sample handling logistics, test sensitivity, and individual behavior, in addition to dynamics of viral transmission. We investigated the interaction between these factors to determine how to optimize reduction of transmission. We show that under idealistic assumptions 70% of transmission may be averted, but under realistic assumptions only 7% may be averted. We show that programs that overwhelm laboratory capacity or reduce isolation of those with minor symptoms have increased transmission compared with those that do not: programs need to be designed to avoid these issues. Our model allows optimal selection of whom to test, quantifies the balance between accuracy and timeliness, and quantifies potential impacts of behavioral interventions.One Sentence SummaryPrograms that overwhelm laboratory capacity or reduce isolation of those with minor symptoms have impaired effectiveness.

Selection of candidate probionts by two different screening strategies from Atlantic cod (Gadus morhua L.) larvae

2010 ◽  
Vol 144 (1-2) ◽  
pp. 153-159 ◽  
Author(s):  
Anders Jón Fjellheim ◽  
Geir Klinkenberg ◽  
Jorunn Skjermo ◽  
Inga Marie Aasen ◽  
Olav Vadstein
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Screening Strategies ◽  
Selection Of

scholarly journals Selection of Best Test Cases using Support Vector Machine for ARPT

2019 ◽  
Vol 8 (3) ◽  
pp. 4265-4271
Keyword(s):  
Support Vector Machine ◽  
Software Testing ◽  
Support Vector ◽  
Test Cases ◽  
Testing Strategy ◽  
Random Partition ◽  
Code Coverage ◽  
Time Consumption ◽  
Branch Coverage ◽  
Selection Of

Software testing is an essential activity in software industries for quality assurance; subsequently, it can be effectively removing defects before software deployment. Mostly good software testing strategy is to accomplish the fundamental testing objective while solving the trade-offs between effectiveness and efficiency testing issues. Adaptive and Random Partition software Testing (ARPT) approach was a combination of Adaptive Testing (AT) and Random Partition Approach (RPT) used to test software effectively. It has two variants they are ARPT-1 and ARPT-2. In ARPT-1, AT was used to select a certain number of test cases and then RPT was used to select a number of test cases before returning to AT. In ARPT-2, AT was used to select the first m test cases and then switch to RPT for the remaining tests. The computational complexity for random partitioning in ARPT was solved by cluster the test cases using a different clustering algorithm. The parameters of ARPT-1 and ARPT-2 needs to be estimated for different software, it leads to high computation overhead and time consumption. It was solved by Improvised BAT optimization algorithms and this approach is named as Optimized ARPT1 (OARPT1) and OARPT2. By using all test cases in OARPT will leads to high time consumption and computational overhead. In order to avoid this problem, OARPT1 with Support Vector Machine (OARPT1-SVM) and OARPT2- SVM are introduced in this paper. The SVM is used for selection of best test cases for OARPT-1 and OARPT-2 testing strategy. The SVM constructs hyper plane in a multi-dimensional space which is used to separate test cases which have high code and branch coverage and test cases which have low code and branch coverage. Thus, the SVM selects the best test cases for OARPT-1 and OARPT-2. The selected test cases are used in OARPT-1 and OARPT-2 to test software. In the experiment, three different software is used to prove the effectiveness of proposed OARPT1- SVM and OARPT2-SVM testing strategies in terms of time consumption, defect detection efficiency, branch coverage and code coverage.

scholarly journals Strategies to reduce the risk of SARS-CoV-2 importation from international travellers: modelling estimations for the United Kingdom, July 2020

2021 ◽  
Vol 26 (39) ◽  
Author(s):  
Samuel Clifford ◽  
Billy J Quilty ◽  
Timothy W Russell ◽  
Yang Liu ◽  
Yung-Wai D Chan ◽  
...  
Keyword(s):  
United Kingdom ◽  
The United States ◽  
The European Union ◽  
Testing Strategy ◽  
Test Scenario ◽  
Uncertainty Interval ◽  
The United Kingdom ◽  
Screening Strategies ◽  
Reduce Risk ◽  
Imported Infections

Background To mitigate SARS-CoV-2 transmission risks from international air travellers, many countries implemented a combination of up to 14 days of self-quarantine upon arrival plus PCR testing in the early stages of the COVID-19 pandemic in 2020. Aim To assess the effectiveness of quarantine and testing of international travellers to reduce risk of onward SARS-CoV-2 transmission into a destination country in the pre-COVID-19 vaccination era. Methods We used a simulation model of air travellers arriving in the United Kingdom from the European Union or the United States, incorporating timing of infection stages while varying quarantine duration and timing and number of PCR tests. Results Quarantine upon arrival with a PCR test on day 7 plus a 1-day delay for results can reduce the number of infectious arriving travellers released into the community by a median 94% (95% uncertainty interval (UI): 89–98) compared with a no quarantine/no test scenario. This reduction is similar to that achieved by a 14-day quarantine period (median > 99%; 95% UI: 98–100). Even shorter quarantine periods can prevent a substantial amount of transmission; all strategies in which travellers spend at least 5 days (mean incubation period) in quarantine and have at least one negative test before release are highly effective (median reduction 89%; 95% UI: 83–95)). Conclusion The effect of different screening strategies impacts asymptomatic and symptomatic individuals differently. The choice of an optimal quarantine and testing strategy for unvaccinated air travellers may vary based on the number of possible imported infections relative to domestic incidence.

scholarly journals Screening Strategies and Methods for Better Off-Target Liability Prediction and Identification of Small-Molecule Pharmaceuticals

2018 ◽  
Vol 24 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Terry R. Van Vleet ◽  
Michael J. Liguori ◽  
James J. Lynch ◽  
Mohan Rao ◽  
Scott Warder
Keyword(s):  
Data Sets ◽  
Multiple Sources ◽  
Drug Candidates ◽  
Critical Gap ◽  
Screening Strategies ◽  
Feasible Option ◽  
Stage Development ◽  
Integrated Screening ◽  
Expensive Process ◽  
Selection Of

Pharmaceutical discovery and development is a long and expensive process that, unfortunately, still results in a low success rate, with drug safety continuing to be a major impedance. Improved safety screening strategies and methods are needed to more effectively fill this critical gap. Recent advances in informatics are now making it possible to manage bigger data sets and integrate multiple sources of screening data in a manner that can potentially improve the selection of higher-quality drug candidates. Integrated screening paradigms have become the norm in Pharma, both in discovery screening and in the identification of off-target toxicity mechanisms during later-stage development. Furthermore, advances in computational methods are making in silico screens more relevant and suggest that they may represent a feasible option for augmenting the current screening paradigm. This paper outlines several fundamental methods of the current drug screening processes across Pharma and emerging techniques/technologies that promise to improve molecule selection. In addition, the authors discuss integrated screening strategies and provide examples of advanced screening paradigms.

scholarly journals FRAX or Fiction: Determining Optimal Screening Strategies for Treatment of Osteoporosis in Residents in Long-Term Care Facilities

2012 ◽  
Vol 60 (4) ◽  
pp. 684-690 ◽  
Author(s):  
Susan L. Greenspan ◽  
Subashan Perera ◽  
David Nace ◽  
Kimberly S. Zukowski ◽  
Mary A. Ferchak ◽  
...  
Keyword(s):  
Long Term Care ◽  
Term Care ◽  
Treatment Of Osteoporosis ◽  
Screening Strategies ◽  
Care Facilities ◽  
Optimal Screening

scholarly journals Analysis and Comparison of Two Artificial Intelligence Diabetic Retinopathy Screening Algorithms in a Pilot Study: IDx-DR and Retinalyze

2021 ◽  
Vol 10 (11) ◽  
pp. 2352
Author(s):  
Andrzej Grzybowski ◽  
Piotr Brona
Keyword(s):  
Artificial Intelligence ◽  
Diabetic Retinopathy ◽  
Pilot Study ◽  
Screening Program ◽  
Diabetic Retinopathy Screening ◽  
Retrospective Comparison ◽  
Screening Strategies ◽  
Set Up ◽  
Selection Of ◽  
Retinopathy Screening

Background: The prevalence of diabetic retinopathy (DR) is expected to increase. This will put an increasing strain on health care resources. Recently, artificial intelligence-based, autonomous DR screening systems have been developed. A direct comparison between different systems is often difficult and only two such comparisons have been published so far. As different screening solutions are now available commercially, with more in the pipeline, choosing a system is not a simple matter. Based on the images gathered in a local DR screening program we performed a retrospective comparison of IDx-DR and Retinalyze. Methods: We chose a non-representative sample of all referable DR positive screening subjects (n = 60) and a random selection of DR negative patient images (n = 110). Only subjects with four good quality, 45-degree field of view images, a macula-centered and disc-centered image from both eyes were chosen for comparison. The images were captured by a Topcon NW-400 fundus camera, without mydriasis. The images were previously graded by a single ophthalmologist. For the purpose of this comparison, we assumed two screening strategies for Retinalyze—where either one or two out of the four images needed to be marked positive by the system for an overall positive result at the patient level. Results: Percentage agreement with a single reader in DR positive and DR negative cases respectively was: 93.3%, 95.5% for IDx-DR; 89.7% and 71.8% for Retinalyze strategy 1; 74.1% and 93.6% for Retinalyze under strategy 2. Conclusions: Both systems were able to analyse the vast majority of images. Both systems were easy to set up and use. There were several limitations to the current pilot study, concerning sample choice and the reference grading that need to be addressed before attempting a more robust future study.

scholarly journals Toward optimal screening strategies for older women

2005 ◽  
Vol 20 (6) ◽  
pp. 487-496 ◽  
Author(s):  
Jeanne S. Mandelblatt ◽  
◽  
Clyde B. Schechter ◽  
K. Robin Yabroff ◽  
William Lawrence ◽  
...  
Keyword(s):  
Older Women ◽  
Screening Strategies ◽  
Optimal Screening

Integration of Lead Discovery Tactics and the Evolution of the Lead Discovery Toolbox

2018 ◽  
Vol 23 (9) ◽  
pp. 881-897 ◽  
Author(s):  
Melanie Leveridge ◽  
Chun-Wa Chung ◽  
Jeffrey W. Gross ◽  
Christopher B. Phelps ◽  
Darren Green
Keyword(s):  
Protein Kinase ◽  
Virtual Screening ◽  
Phenotypic Screening ◽  
Library Screening ◽  
Success Rates ◽  
Domain Family ◽  
Lead Discovery ◽  
Fragment Screening ◽  
Screening Strategies ◽  
Selection Of

There has been much debate around the success rates of various screening strategies to identify starting points for drug discovery. Although high-throughput target-based and phenotypic screening has been the focus of this debate, techniques such as fragment screening, virtual screening, and DNA-encoded library screening are also increasingly reported as a source of new chemical equity. Here, we provide examples in which integration of more than one screening approach has improved the campaign outcome and discuss how strengths and weaknesses of various methods can be used to build a complementary toolbox of approaches, giving researchers the greatest probability of successfully identifying leads. Among others, we highlight case studies for receptor-interacting serine/threonine-protein kinase 1 and the bromo- and extra-terminal domain family of bromodomains. In each example, the unique insight or chemistries individual approaches provided are described, emphasizing the synergy of information obtained from the various tactics employed and the particular question each tactic was employed to answer. We conclude with a short prospective discussing how screening strategies are evolving, what this screening toolbox might look like in the future, how to maximize success through integration of multiple tactics, and scenarios that drive selection of one combination of tactics over another.

Sign in / Sign up

Export Citation Format

Share Document